package org.eoti.ai.genetic.gp;

import java.util.ArrayList;
import java.util.List;

/**
 * The MIT License
 * <p/>
 * Copyright (c) 2009 Malachi de AElfweald (malachid@gmail.com)
 * <p/>
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated
 * documentation files (the "Software"), to deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to the following conditions:
 * <p/>
 * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the
 * Software.
 * <p/>
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
 * WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
public class Crossover<DATA,FITNESS>
extends Evolution<DATA,FITNESS>
{
	public List<Program<DATA, FITNESS>> evolve( List<Program<DATA, FITNESS>> source )
	{
		ArrayList<Program<DATA,FITNESS>> list = new ArrayList<Program<DATA,FITNESS>>();

		Program<DATA,FITNESS> one = source.get(0).copy();
		Program<DATA,FITNESS> two = source.get(1).copy();

		Node<DATA,FITNESS> randomParent1Node = findRandomParentNode(one);
		Node<DATA,FITNESS> randomParent2Node = findRandomParentNode(two);

		int pos1 = RandomNumber.INSTANCE.nextInt(randomParent1Node.size());
		int pos2 = RandomNumber.INSTANCE.nextInt(randomParent2Node.size());

		Node<DATA,FITNESS> randomNode1 = randomParent1Node.get( pos1 );
		Node<DATA,FITNESS> randomNode2 = randomParent2Node.get( pos2 );

		randomParent1Node.set( pos1, randomNode2 );
		randomParent2Node.set( pos2, randomNode1 );

		list.add(one);
		list.add(two);
		
		return list;
	}

}
